The field of this invention is cable trays for low voltage cables and more particularly cable trays that provide service loops.
Low voltage cables are cables that carry approximately 48 volts or less, although in some contexts the definition might be more restrictive, i.e. 24 volts or less. This is distinguished from power cables that are used to supply high voltage electricity to operate something such as an appliance or lighting. A low voltage cable, in contrast, carries a low amount of voltage and its purpose is primarily to carry data. A low voltage cable carries an electrically conductive wire inside a jacket. An example of a low voltage cable is a Category 5 copper cable called in the industry xe2x80x9cCAT 5 Copperxe2x80x9d. Another example is a Category 3 voice cable. Another example is a fiber optics cable. Even a video camera used for security would have a low voltage cable. A common example of low voltage cabling is the cables that run from computer work stations in an office. If the computers need to communicate with one another and to a server computer, then low voltage cables are used to connect them to the common server at the termination points. Telephone lines running from a phone in an office are also connected by low voltage cables to a common termination point.
The cables that run from work stations can number in the hundreds for large companies. Each of the cables emanating from a work station goes to termination points located in a data closet that could be in an out of the way area of the office on a wall between the visible drop ceiling and the xe2x80x9crealxe2x80x9d ceiling. For the remainder of this patent application, these situations are called xe2x80x9csmall applicationsxe2x80x9d, where the number of cables is not so large that they cannot terminate a simple data closet on a wall. xe2x80x9cLarge applicationsxe2x80x9d shall refer to cabling done for large offices with large cables from large numbers of work stations or other sources of cables, where the termination points are so numerous and the cabling so bulky that the termination points are located in data cabinets located underneath ladder racks that are housed in a special room, called a data center, devoted exclusively to this purpose.
It is generally recognized that there is a need for a service loop at cable termination points. This means that there is a need for extra wire of each cable to be left at the termination point whose purpose is to make it easier to do service work, such as the rearrangement of the cabling, later. Suppose for example that there are cables 1 through 52 and they terminate in termination points which we arbitrarily label using the letters of the alphabet A through Z and then AA through ZZ. Normally cable 10 is plugged into termination point J and cable 40 is terminated at termination point NN. Suppose the client calls for service requiring a rearrangement of the computer lines such that cable 10 now needs to be plugged into termination point NN and that requires the re-cabling and re-matching of many other cables to different termination points. It would be much easier to perform the service request if a certain amount of slack were left over to do that. This called a service loop. The term xe2x80x9cservice loopxe2x80x9d shall be defined in this patent application as any excess cable left for service or other future considerations.
Service loops are xe2x80x9cindustry standardxe2x80x9d with respect to cabling done in the smaller applications where the termination points are located in a data closet usually attached to a wall above a drop ceiling. Accordingly, by industry standard if a service loop was not left at the termination point, the cabling job was shoddy and un professional. Even if a service loop was left, however, it does not necessarily mean the cable job was up to par. There are different ways to leave service loops. If the arrangement of the end of the cables is neat and efficient, that is considered fine. If the arrangement of the end of the cables is messy and totally disorganized and jumbled, the job was still done poorly. Empirically, the manner in which service loops are arranged at termination points in cabling jobs for the so-called smaller applications unfortunately tend to have two serious drawbacks.
The first drawback is that the service loop arrangement is typically tied together in a messy jumble which results in the cabling looking unprofessional and unappealing aesthetically. This is not simply an issue of abstract beauty. The cabling industry prides itself on organizing the cables well. A general contractor hired to build office space does not typically hire a company to do the cabling work for the office before seeing examples of the previous cabling work that company did. Aesthetics and how professional the job looks is central to an evaluation of the quality of the previous cabling work. In addition, for practical reasons, a general contractor would not want to see a cabling job revealing a messy service loop because it suggests a higher than desirable expected cost of future service in the likely event rearrangement of the cables is needed. Cabling is a labor intensive endeavor and labor typically runs $125 per hour, at least in New York City as of the time of the writing of this patent application.
The second drawback is that an excessive number of bends in a low voltage cable distorts the flow of data through the cable. When dealing with a large amount of cables that are together, the weight of the cables can be significant and can damage a particular cable if there is bending. If the cabling, meaning arranging the cables at their termination points, is not done properly it can damage the cables. Hence there is a strong need for aesthetically appealing and organized cabling at the termination point of the cables in smaller applications that terminate in a data closet.
Currently data closets do not have any support structure that permits a neat and efficient service loop to be left.
With respect to the very large applications that handle a large number of cables wherein data cabinets are lined up under ladder racks that run across a data center to accommodate hundreds of cables being terminated, service loops are simply omitted as a matter of course because it is understood that although service loops very beneficial, there is simply no room for them. Alternatively, service loops are left in the data cabinets under the ladder racks but they are haphazard and not neat because there is no support structure that makes it possible to leave a neat and efficient service loop.
It would advantageous to have a way to allow for a service loop to be left in the large cabling applications in data centers. In addition, for both larger and smaller applications, it would be advantageous for there to be a way in which it was easy to neatly and efficiently organize cables at their termination point with a service loop. Given the degree to which aesthetics, neatness and efficiency play a role in the cabling industry, having these advantages dramatically increase the value of a cabling company""s appeal.
The present invention address both of the aforementioned applicationsxe2x80x94larger and smallerxe2x80x94and solves the above-mentioned problems as well as providing other advantages. The present invention features for the smaller applications a wall-mounted service loop tray for a data closet used to provide a service loop for a moderate amount of cables. The present invention also features for the larger applications a service loop tray assembly that provides an aesthetically appealing and highly organized service loop for a large amount of low voltage cables that terminate in a data cabinet in a data center. In the present invention, an assembly of cable trays is provided for the larger application which is essentially an unconnected plurality of individual cable trays similar to the ones that are featured for the smaller application.
In a data center, a series of channel-shaped cable trays hold sets of cables that are resting on ladder racks having data cabinets positioned underneath the ladder racks at a series of junctures along the ladder rack. In a main embodiment each cable tray has a substantially u-shaped cross section. The cable tray is mounted to the ladder rack at opposite sides of the ladder rack and each of the cable trays includes a substantially level service loop section, a cable access ramp and a cable drop lip. The service loop section is connected to a cable access ramp and to a cable drop lip. Each cable drop lip is situated so as to turn and guide each set of cables into the particular data cabinet to terminate the cables . The cable access ramp of each cable tray rises sufficiently to avoid interference between the service loop section of the first cable tray and the next set of cables that passes the first cable tray and continues to the next cable tray at a further juncture along the ladder rack.
The following important objects and advantages of the present invention are:
(1) to provide an apparatus for arranging neatly and in an organized way a large amount of low voltage cables adjacent their termination points;
(2) to provide an aesthetically appealing apparatus for arranging a large amount of low voltage cables adjacent their termination points;
(3) to provide a cabling tray assembly that provides for a service loop when cabling low voltage cables that terminate from ladder racks into data cabinets in a data center;
(4) to provide a cable tray for service loops comprised of a cable access ramp, a cable drop dip and a cable service loop section
(5) to provide a cable tray assembly having a series of cable trays for use on ladder racks in data centers wherein the cable access ramp of one cable tray in the assembly does not interfere with the next set of cables that continues to the adjacent cable tray;
(6) to prevent damage to cables from unnecessary bending stemming from a messy cabling job;
(7) to provide a cable tray and a cable tray assembly that can be used for any low voltage cable; and
(8) to provide a cable tray and cable tray assembly that can be used for any amount of cables
(9) to provide a cable tray and a cable tray assembly that is of very simple construction and is easy to manufacture